I took the valve control off our water heater in order to install a new 3" pipe nipple and coupling because the old ones were rusting so badly. The new parts are not metal so never any rust will come from the water heater tank drain. Also, using these two pieces plus a plastic screw-in drain plug enables draining the tank without flooding and shorting the valve.
NOW THE PROBLEM: Copious amounts of soot appeared above the vent grill and on up the L.R. window. The soot wipes off but it shouldn't happen. I believe I didn't provide enough of a gap between the valve jet output and the tube going to the tank innards. I just reset the gap to about 3/32" yesterday but haven't tried the heater yet because I had drained the fresh water system.
So, anybody know the approximate gap?
Does your water heater have a slide that allows you to adjust the air and therefore the air to fuel mixture?
Like Brett said you adjust the air for combustion with the slotted sliding sleeve.
Yup..sliding adjustable multi-slotted sleeve held in desired position by a small 3/16 hex head sheet metal screw.
I like a lighter blue flame that is a little noiser but does not pop every few seconds. This works by moving the sleeve away so more air can be sucked in and the mixture is leaner. Check to see that no bugs or critters are living in the exhaust of the heater.
Pierce